// Initialisation of Array
let differentNumbers = [-1, 3, 29, -3, 15]

// Root function
func filterArray(array: [Int], condition: (Int) -> (Bool)) -> [Int]{
    var filteredArray: [Int] = []

    for elementOfArray in array {
        if condition(elementOfArray) {
            filteredArray.append(elementOfArray)
        }
    }
    return filteredArray
}


// 1. First version
func isThisNumberNegative(number: Int) -> Bool {
    return number < 0
}

let resultArrayOfNegativeNumber = filterArray(array: differentNumbers, condition: isThisNumberNegative)

print(resultArrayOfNegativeNumber)



// 2. Second version
let resultArrayOfNegativeNUmbersVersionTwo = filterArray(array: differentNumbers, condition: { $0 < 0})
print(resultArrayOfNegativeNUmbersVersionTwo)



// 3. Third version
let resultArrayOfNegativeNumberVersionThree = filterArray(array: differentNumbers) { $0 < 0 }
print(resultArrayOfNegativeNumberVersionThree)